Improvement in burglar-alarms



/M MQW/uf W @MZ W. D. WRIGHT.

BURGLAR-ALARM.

No. 177,051. Patented May'2,1876.

N.PE\ERS. PHDTO-LITHOGRAFHER, WASHINGTON D C UNITED STATES PATENT OFFICE.

WILLIAM D. WRIGHT, OF BALTIMORE, MARYLAND.

IMPROVEMENT iN BuRGLARfALARMs.

Specification forming part `of Letters Patent No. l77,05l, dated May 2, 1876 application filed March 17, 1876.

To all whom fit may concern Be it known that I, WILLIAM D. WRIGHT, of Baltimore, in the county of Baltimore and State of Maryland, have invented certain new and useful Improvements in Burglar-Alarms, and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to which it appertains to make and use the same,

reference being had to the accompanying drawings, and to letters ot' reference marked thereon, which t'orm a part of this specification, and in which- Figure lis a side elevation. Fig. 2 is a longitudinal vertical section. Fig. 3 is a top plan, the hammer being open; and Fig-4 is a perspective view, showing the alarm set for action in a door-jamb.

Similar letters of referenceindicate correspending parts in all the Iigures.

The object of my invention is to construct in a compact shape an apparatus that, when properly set, will easily explode a cartridge, and which, further, may be set iu a door-jamb, windowesash, Src., in such a manner that when the door or window is opened, no matter how cautiously, it will instantly explode, thus warning the inmates of the house in which it is used that the house is being entered. The manner of constructing and operating my improved burglaralarm is as more l'ully and clearly hereinafter Set forth.

In the drawings, A is the body of my improved device, one end of which is tapered off, so as to form a narrow end or point, B, which may easily be inserted into a narrow aperture.

The body A has alongitudiual slot, C, extending almost through the entire length of the body. In the end of this slot which is nearest the blade B is pivoted the hammer D, having steel tooth e, by which the cartridge is exploded. This (the cartridge) is inserted into the cylindrical slot F in body A in front of slot C. The hammer D is operated by a strong steel spring, d, secured below it 1n slot O.

In the dovetailed slot g in hammer D is inserted a metallic lever, G, by means of which the hammer may be raised to the position shown by the dotted lines in Fig. 1. In

raising hammer D, lever G is carried down fiat upon blade B, as also shownin dotted lines in Fig. 1. Lever Gis made of alength sufficient to reach the end or. point of blade B when brought to the position mentioned.

It must be suificiently narrow to enable it tov be inserted, together with blade B, into a narrow aperture between the door and jamb.

The mode of setting my improved burglaralarm for action is clearly indicated in Fig. 4, by 'which it will be Seen that the hammer is raised and lever G and blade B inserted together between the lock and keeper ot' an ordinary door. In order to prevent it from dropping on the floor, it may be affixed by means of asmall cord to the lock ofthe door. The action of the spring d has a tendency to force lever G and blade B apart-that is, sufficient to keep the apparatus in position. When the door is opened the pressure upon lever G is released, and hammer vD is forced down by the spring, thus exploding the cartridge, which has been previously inserted into the cylindrical slot F.

When properly set, my improved device cannot possibly be exploded by accident, but it must necessarily be exploded when a door or window is opened from the outside, thus arousing the inmates ofthe house that is being entered. Its construction is simple and cheap, and it is easilyv set for action without the aid of any complicated or expensive machinery.

Having thus described my invention, I claim and desire to secure by Letters Patent ot'v the United States- 1. In combination with body A, the hammer D, having tooth c, and removable lever Gr, substantially as and for the purpose specified.

2. The burglar-alarm herein described, consisting of body A, having slots C F, tapering blade B, pivotcd hammer D, spring d, and removable lever G, all combined and arranged to operate substantially. as and for the purpose shown and specified.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in presence of two witnesses.

WILLIAM D. WRIGHT.

Witnesses:

WM. BAGGER, C. A. SNOW. 

